江苏地区夏季雷暴的雷达回波特征研究

Study on radar echo characteristics of summer thunderstorms in Jiangsu

为提高江苏省地区雷暴监测预警能力,利用S波段双偏振多普勒天气雷达雷暴探测回波资料和闪电定位资料对江苏省2014年7—8月的夏季雷暴进行特征研究,研究了雷暴反射率核心区域的演变特征、不同温度层反射率因子与地闪频数随时间的相关性问题和雷暴发展过程云内粒子的演变特征。研究结果表明:在雷暴成熟之前,雷暴的反射率因子核心区域的强度、高度和云顶高度不断增加,以及对流发展旺盛,当雷暴成熟之后,雷暴的强反射率因子核心的强度和对应高度就会不断降低,雷暴将趋于消散;雷暴能够发生闪电的主要特征是40 dBZ回波顶高度要高于0℃温度层高度;雷暴中闪电的产生和霰粒子有着密切的联系,尤其是湿霰粒子。

In order to improve the monitoring and early warning ability of thunderstorms in Jiangsu,the characteristics of thunderstorms in summer from July to August 2014 in Jiangsu were studied by using S-band dual polarization Doppler weather radar thunderstorm detection echo data and lightning location data.The evolution characteristics of thunderstorm reflectivity core,reflectivity factor of different temperature layers and ground strobe frequency were studied.The correlation with time and the evolution characteristics of cloud particles during the development of thunderstorms.The results show that before the maturity of thunderstorms,the intensity,height and cloud top height of the core region of the reflectivity factor of thunderstorms increase continuously,and the convection develops vigorously.After the maturity of thunderstorms,the intensity and corresponding height of the core of the strong reflectivity factor of thunderstorms will decrease continuously,and thunderstorms will tend to dissipate.The main characteristic of lightning occurrence is that the echo top height of 40 dBZ is higher than the temperature layer height of 0℃.The lightning generation in thunderstorms is closely related to graupel particles,especially wet graupel particles.